NEW YORK  - If a girl wants to try her hand at baseball or ice hockey, she's likely to be praised as plucky. But if a boy likes the color pink?

Well, that's a toenail of a different color.

Last month, J. Crew unleashed a furor when a promotion depicted its creative director, Jenna Lyons, painting her 5-year-old son Beckett's toenails with pink nail polish. "Lucky for me, I ended up with a boy whose favorite color is pink," the caption read.

Dr. Keith Ablow, a psychiatrist and regular guest on Fox News, didn't approve.

"It may be fun and games now, Jenna, but at least put some money aside for psychotherapy for the kid," he wrote on Foxnews.com. "This is a dramatic example of the way that our culture is being encouraged to abandon all trappings of gender identity."

In fact, Lyons and her son had stepped on a cultural land mine. Gender stereotypes for America's children are less rigid than in the past, but they remain a pervasive part of popular culture and a benchmark for parents. Moreover, the changes in recent decades have been more dramatic for girls than boys.

So Ablow quickly found support. One Million Moms, an offshoot of the conservative American Family Association, urged followers to write protest letters to J. Crew and asserted that "nontraditional activities ... can be destructive and damaging to a child's identity and self-esteem."

Just as quickly, there was a backlash from people who liked Beckett's pink toenails. Hundreds of people accepted a Facebook invitation to join "Pink Toenail Polish Day" on Monday, and Anne Fausto-Sterling, a professor of biology and gender studies at Brown University, urged Lyons' critics to "take a deep breath" and not worry if kids don't always fit a "cardboard cutout stereotype of gender roles."

"Kids explore, sample, test and learn," she wrote in a Psychology Today blog. "They should have the freedom to do this and the strength to grow into interesting human beings."

Across the spectrum of politics and parenting philosophies, it's a topic that captivates people.

"For girls nowadays, it's OK to play with boys' toys, dress like boys, talk like them - it's often encouraged," said Isabelle Cherney, a Creighton University psychologist. "Boys have to walk a much finer line, and their fathers tend to be more stereotyped, telling them not to deviate from what's typically seen as masculine."

For little girls and their parents, there's ample room to maneuver. Ultra-feminine toys and activities abound, along with an ever-growing range of "tomboy" sports options and other pursuits that in the past were mostly the domain of boys.

"The norms of femininity have expanded much more than the norms for masculinity - a lot more androgyny is allowed for girls," said Judith Stacey, a professor of social and cultural analysis at New York University.

"With boys, it's not seen as OK to wear skirts, play with princesses' wands," she said. "There's still a lot of anxiety about being sufficiently masculine."

The trends are reflected in career aspirations. Women now make up close to half the enrollment in U.S. law and medical schools, up from less than 25 percent a few decades ago, yet men continue to shun nursing as a career, comprising only about 8 percent of registered nurses.

William Pollack, a professor in the Psychiatry Department at Harvard Medical School, has written extensively about the challenges facing American boys and hopes the stereotypes affecting them are loosening. "Keeping boys in the gender straight jacket was not good for them," he said.

"If a boy wants to dress up now and then in his mother's clothes, what he's doing is identifying with one of the most loved people in his life - he's not dis-identifying with being a boy."

Pollack said many fathers are torn over gender-role issues, supporting the concept of less rigid stereotypes yet worried that their sons might be ostracized if they partake in activities viewed by their peers as unmasculine: "We still socialize boys to follow their more aggressive side rather than their more thoughtful and caring side. We're basically telling boys that the worst thing they can be is a girl."

Feminists with sons find themselves swimming against the tide. Imani Perry, a professor at Princeton's Center for African American Studies, says she teaches her sons, 4 and 7, to believe in gender equality, but finds it challenging that many of their friends' parents tend to reinforce stereotypes.

"My sons have been so disappointed by gender-specific birthday parties ... and confused by the princess culture their girl friends are so often caught up in," Perry wrote in an e-mail.

Amy Richards, mother of 5- and 7-year-old sons in New York City, is a feminist activist and author of "Opting In: Having a Child Without Losing Yourself." A former college soccer player, Richards is pleased that her sons are good athletes, but also is wary of lapsing into gender stereotypes. For example, she made a point of taking them to see the New York Liberty, a women's pro basketball team.

"I try not to overemphasis masculinity and devalue femininity," she said. "I don't want to buy only 'boy toys' for them ... I've never purchased an action hero figure."

In Chicago, social worker Keisha Farmer-Smith counsels adolescent girls at work. At home, she's a single mom raising sons Kaleb, 7, and Khalil, 12 - and encouraging them to think creatively about gender roles.

She recalled how Khalil, at 5 or 6, had a cuddly doll named Mikey that rarely left his possession.

"My ex-husband was so upset that I would allow him to have this doll," Farmer-Smith said. "It came down to me supporting my son. He said, 'I want to be a good parent. I love Mikey. I want him to see me play ball."'

Glenn Stanton, director for family formation studies at the Christian ministry Focus on the Family, believes male/female differences should be emphasized to children, rather than blurred, on the premise that each gender has essential strengths.

However, Stanton, who has a son and four daughters, says he welcomes a move away from polarized gender roles - what he calls the "pretty in pinks" and "macho Joes."

"We're moving away from the crazy stereotypes," he said. "But we're not saying that gender doesn't matter."

For Keith Ablow, blurring of gender roles could have momentous long-term consequences.

"It will be a very big deal if it turns out that neither gender is very comfortable anymore nurturing children above all else," he wrote, "and neither gender is motivated to protect the nation by marching into combat against other men and risking their lives."

"Maybe we'll all have shiny, colored lips, though, and pierced ears and perfect eyebrows."